Hi all,
does it make sense to use Hypex Class-D modules with linear PSU instead of their own SMPS ones ? Especially the bigger ones which run on unregulated rails. The PSU part might be big and heavy but does it bring any real advantage compared to a SMPS one ?
The forum's search engine is bringing up some threads that might relate to this (for me to consider posting a new thread) but the same question was asked in the Class D topic in 2015 without answer.
Maybe this time here and now somebody has already some experience feeding "big" Class D amps from linear PSUs. Any kind of - of course. (Hypex is just one I'd like to use, not bought yet). Thanks.
does it make sense to use Hypex Class-D modules with linear PSU instead of their own SMPS ones ? Especially the bigger ones which run on unregulated rails. The PSU part might be big and heavy but does it bring any real advantage compared to a SMPS one ?
The forum's search engine is bringing up some threads that might relate to this (for me to consider posting a new thread) but the same question was asked in the Class D topic in 2015 without answer.
Maybe this time here and now somebody has already some experience feeding "big" Class D amps from linear PSUs. Any kind of - of course. (Hypex is just one I'd like to use, not bought yet). Thanks.
21" woofer. This Class D performance built as a Mosfet AB would produce pretty much heat when idle, too.
Interestingly
Personally running 4 x 21" woofers as pet HiFi, 7000w PMax, each in reflex 600 litre enclosures, bass, 20Hz to 250Hz, Neo magnet monster PA Bass makers
Can and do run them on a 10w per channel class D plugged into a 24v, 50w brick SMPS, with jaw dropping + 95dB performance, for fun and with a little seriousness. Outlay $35
If the SMPS or D Class drop dead, no loss, however
Professionally the same speaker set run on 2 x Holton Class AB Power Amplifiers, with 1 x 250w RMS Amplifier and 625 VA Transformer (linear Supply) per driver, this for gut churning +125dB @10m performance.
Like both set ups very much,
1,D Class is rather miserly on power, generally listening levels less than 10w on the off grid power supply (great in Winter where power is a premium)
2, AB Class is static at 200w, idle, with spikes to 2Kw, rather hungry on juice
Thing is over time the practical experience of using professionally D Class to drive speakers generally you need to carry a spare and repairs can be very challenging for even the most hardened Technicians
Never had any problems with the Class AB in use, ever
Sound Quality
Well, the debate continues but the both set ups (large or small) D Class with internal or external SMPS sound good, really good.
It's like comparing a red apple and a green apple, both are sweet and crunchy have similar texture and taste. End of day though the AB just controls the cones in a more "fitting and controlled" manner. The D Class can be dry sounding and occasionally lack grip, particularly if comparing say, a 1Kw D Class into 4 Ohms @1%THD and the 250w/625VA into 8 Ohms @ 0.01THD. Even match power wise, surprisingly
How a D Class HyperX or whatever responds to a linear PSU is intriguing, with regard to end Sound Quality. IMHO there is no way to know unless you shell out the coin for something like a 2Kva Toroidy Supreme Transformer, high speed rectifier and line up those capacitors...
To be continued . . .
wicked looking D Class module :0, give it a run !!!
Personally running 4 x 21" woofers as pet HiFi, 7000w PMax, each in reflex 600 litre enclosures, bass, 20Hz to 250Hz, Neo magnet monster PA Bass makers
Can and do run them on a 10w per channel class D plugged into a 24v, 50w brick SMPS, with jaw dropping + 95dB performance, for fun and with a little seriousness. Outlay $35
If the SMPS or D Class drop dead, no loss, however
Professionally the same speaker set run on 2 x Holton Class AB Power Amplifiers, with 1 x 250w RMS Amplifier and 625 VA Transformer (linear Supply) per driver, this for gut churning +125dB @10m performance.
Like both set ups very much,
1,D Class is rather miserly on power, generally listening levels less than 10w on the off grid power supply (great in Winter where power is a premium)
2, AB Class is static at 200w, idle, with spikes to 2Kw, rather hungry on juice
Thing is over time the practical experience of using professionally D Class to drive speakers generally you need to carry a spare and repairs can be very challenging for even the most hardened Technicians
Never had any problems with the Class AB in use, ever
Sound Quality
Well, the debate continues but the both set ups (large or small) D Class with internal or external SMPS sound good, really good.
It's like comparing a red apple and a green apple, both are sweet and crunchy have similar texture and taste. End of day though the AB just controls the cones in a more "fitting and controlled" manner. The D Class can be dry sounding and occasionally lack grip, particularly if comparing say, a 1Kw D Class into 4 Ohms @1%THD and the 250w/625VA into 8 Ohms @ 0.01THD. Even match power wise, surprisingly
How a D Class HyperX or whatever responds to a linear PSU is intriguing, with regard to end Sound Quality. IMHO there is no way to know unless you shell out the coin for something like a 2Kva Toroidy Supreme Transformer, high speed rectifier and line up those capacitors.
.. To be continued . . .
wicked looking D Class module :0, give it a run !!!
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Much respect 125dbmonster, you just gave me a perfect answer on my question. 
I'm happy to see even more crazy people out there than myself
My setup would be 2x 21" (one per side), part of an active 3-way stereo.. the RCF LF21X451 in a beautiful, big, tall 450L bass reflex box tuned to Fs=28Hz (exactly the resonance freq). I'm not aiming for sub-bass regions however 20Hz will still be achievable at reasonably good levels, -3dB point is at around 24Hz if I remember my simulation correctly. (Just reinstalled Windows and haven't installed WinISD back yet).
Sensitivity is 97dB on datasheet, according to simulation it's rather at around 95dB built into the big box - plenty of SPL even with a small amp just like you did too (haha, what a great idea..!!)
And actually yeeees, hey, .. I've just bought the cheapest, acceptably sounding Class D modules on aliexpress, 2 little TDA8932 modules, both work fine.. driven to get around 20Watts into 8 Ohms. I might try the little 'beasts' lol
My friends won't believe what I'm using for this big system
Well, for the midrange I'll use parallel pushpull tube monoblocks, for the 98dB tweeter a ~200W Mosfet so the big power for the 21" will be needed I think when driving it loud.
But I think it's very clever what you just wrote: on small signal levels it's better to use small Class D 'cause - apparently and I keep hearing this from a few folks - when they have a failure that's it, almost impossible to repair. At least I won't try that. So then let's make it cheap.
So now you made me strongly re-think my amp setup, maybe I'll also opt for a big Mosfet AB for the woofer too. Uh.
Because most of the time the system will run on small power, playing background music, sometimes a very little bit more.. movie power or "party power" would only be needed on weekends.
Thanks for this tip, it was great to read .. twisted my mind(set) a little bit
I'm happy to see even more crazy people out there than myself My setup would be 2x 21" (one per side), part of an active 3-way stereo.. the RCF LF21X451 in a beautiful, big, tall 450L bass reflex box tuned to Fs=28Hz (exactly the resonance freq). I'm not aiming for sub-bass regions however 20Hz will still be achievable at reasonably good levels, -3dB point is at around 24Hz if I remember my simulation correctly. (Just reinstalled Windows and haven't installed WinISD back yet).
Sensitivity is 97dB on datasheet, according to simulation it's rather at around 95dB built into the big box - plenty of SPL even with a small amp just like you did too (haha, what a great idea..!!)
And actually yeeees, hey, .. I've just bought the cheapest, acceptably sounding Class D modules on aliexpress, 2 little TDA8932 modules, both work fine.. driven to get around 20Watts into 8 Ohms. I might try the little 'beasts' lol
My friends won't believe what I'm using for this big system Well, for the midrange I'll use parallel pushpull tube monoblocks, for the 98dB tweeter a ~200W Mosfet so the big power for the 21" will be needed I think when driving it loud.
But I think it's very clever what you just wrote: on small signal levels it's better to use small Class D 'cause - apparently and I keep hearing this from a few folks - when they have a failure that's it, almost impossible to repair. At least I won't try that. So then let's make it cheap.
So now you made me strongly re-think my amp setup, maybe I'll also opt for a big Mosfet AB for the woofer too. Uh.
Because most of the time the system will run on small power, playing background music, sometimes a very little bit more.. movie power or "party power" would only be needed on weekends. Thanks for this tip, it was great to read .. twisted my mind(set) a little bit
Btw I thought Class D has better woofer control due to higher as usual damping factor (big feedback) so even your small D-s are having a better control over the woofers (within their usable power range of course) than AB. Just as I learned 'til now. That's the second reason why I chose class D for bass.. also pretty immune to the woofer's impedance peak.
The twisted part is the small D Class is more than enough in that small room, to drive bone shaking SPL from 20Hz
The reason for this is the off grid power system cannot run the big amps in the middle of Winter. Was quite taken by the outcome of the $35 amp /power supply set up, mostly the tiny amount of watts of consumption.
Spring is here so, time to set up the big guy amps again and warm the system for it's annual outings at off grid hippie festivals running on battery/solar
The reason for this is the off grid power system cannot run the big amps in the middle of Winter. Was quite taken by the outcome of the $35 amp /power supply set up, mostly the tiny amount of watts of consumption.
Spring is here so, time to set up the big guy amps again and warm the system for it's annual outings at off grid hippie festivals running on battery/solar
Enjoy your 21's there, there is nothing quite like them in a large enclosure
Picture shows tiny amp on the floor and the 2 large amps in the rack
Yes there are others that think in a similar manner, very nice to meet you
Whoaa, looks badass
Omg sure, just recognizing you're on the southern hemisphere so spring is coming .. lol weird lol .. I hope one time I can visit Australia and the whole region there
It's already getting wet-cold here with fogs, brrr.. late autumn season. But I'm still on the grid.. great to see you made this very logical decision to use Class D for moderate SPL needs. Imagine powering up 6 monoblocks, all Class AB which alltogether consume a pretty large amount of energy while still idling only so Class D is just the best solution I would also go if I were you. Great idea. (Else it's like having at least one electric heater, or a hair dryer always ON).
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